hissing battery

[chris71]

the battery in my chevelle is making some bubbling noises and hissing noises, nothing consistant, a hiss here for a few seconds, some erratic bubbling noises, and it is leaking a little from one side (out of the cap i am assuming) the battery is 4 years old and hasnt seen much use in the past 4 years just ocasional cruises, no bulging of the battery or wierd voltage readings, 12v, off, 14v while running, it will hiss and moan long after the car has been shut off, like a week after, started it up last night and it was hissing more. what would cause this, looks like i am buying a new one, what do you guys think

[69ShortStep]

My battery started making those noises and soon after I started smelling that "Rotten Egg" smell that comes from a cooked battery. My generator was sending too much juice and I converted to an alternator and bought a new battery. If your battery is starting to be cooked, don't ignore it as it can be very dangerous. My engine compartment shows the scars but it could easily of been me. Most auto parts stores will check the battery/alternator for free.

[Bishops Trucks]

It sounds like the alternator is overcharging or check the voltage regulator.

[Bus Ted Knuckle]

You battery is being over charged. Check your alternator and you VR(if you still have one)

[chris71]

Originally Posted by Bus Ted Knuckle

You battery is being over charged. Check your alternator and you VR(if you still have one)

thats what i thought but my aftermarket volt gauge inside the car says 12volts at rest. 14 volts when running, this isnt overcharging is it?

[Woody]

If the battery is hissing it is boiling the acid and putting off gases that are EXTREAMLLY EXPLOSIVE!!! A spark will blow it up in a heart beat. (Been there, Done that!!) You may have bad Diodes in the Alternater sending the Battery AC instead of DC, which will ruin the battery very soon.

Also any acid/water that is boiling out will eat everything in site, such as battery box, lower fender......

Have the Alt and Regulater checked.

[longorange68]

DO NOT OPEN BATTERY COVERS WHILE THE BATTERY IS STILL IN THE CAR!!!!! Wear gloves and goggles, not glasses, at the very least. Lead acid batteries off-gas hydrogen, and the explosion will not be great, but it WILL sling acid all over everything in your engine bay. I work with 130 volt DC battery banks every day as a substation operator, and we have a two man rule. Anytime you are near the batteries we use two people as a safety measure. Sounds like overkill, but have you ever had acid in your eyes, and travelled somewhere to a safety wash by yourself? 9 out of 10 people can't do it before permanent eye damage sets in. The second persons drags your butt out, and starts hosing you down. They will usually have to force your eyelids open manually since your bodies reaction to foreign objects in the eyes is to clamp down tight. Enough of the doom and gloom though, I also suspect bad diodes in the alternator. For it to physically hiss, you will need high voltage as well as heat, in this case the heat would be cause by the natural plate resistance and arcing from the positive and negative plates. I would venture to say that your battery is toast., However, do not replace the battery and continue to drive the car without having the diodes checked in the alternator. Well, unless you really like to buy batteries.

[dan42]

Can you say, Ka-BOOM?

[OrangeCrush1970]

My battery did the same thing. I had a bad voltage regulator and it fried my battery. Throw a new voltage regulator on there, they are cheap! Unfortunatly the battery is probably no good...don't continue to run your car like that, the battery could and will probably explode and that's bad news bears right there.

[chrislehr]

bad voltage regulator.

[Sammy]

I feel sorry for the battery box area. Most likely cooked with acid that & core support.

[special-K]

The battery is over caharging.Ignore the incorrect gauge.It`s usually the volt.reg.,could be the alt.I changed to internal volt.reg.when mine did that.Your battery won`t take much of that.

[Wreckless_71]

Yes... please be very safe when handling anything battery related. My dad had one blow up on him when he was a young guy and he has severly scarred his arms from the battery explosion. Not to mention the fact that he almost lost his vision...

[chris71]

Ok, took the battery and alt. to napa, the tested the bat. not putting any load on it, they said it was good, i got a new one. they tested the alt and said it was good, i specifically asked if their machine would test the diode and they said yes, its good. so i bolted it back up. now, what is the best way to test the voltage reg.? which looks brand new by the way, should i test the voltage at the battery with elevated rpms, test the output of the voltage reg. at the cable coming out of the voltage reg. should these be the same voltage?

[elf w/capital T]

did replacing all that work? did you find out why or how it all took a dump? mines doin the same and well all i did was re run new wires from the alt to the voltage regulator, it worked before...but hmmm

[chris71]

Elf, yeah it worked out fine just replacing the battery, never had a problem since i swapped for a new battery, i dunno, maybe it just had a bad cell. I checked battery cables and alt wires and all seemed fine so I didn't even mess with them.

[special-K]

Regardless of the cause,this symptom indicates an overcharging battery. What you are gearing is boiling battery acid (bubbling) and the pressurized gases created by evaporation (hissing) trying to escape. It's a dangerous situation.

[406 Q-ship]

Originally Posted by special-K

Regardless of the cause,this symptom indicates an overcharging battery. What you are gearing is boiling battery acid (bubbling) and the pressurized gases created by evaporation (hissing) trying to escape. It's a dangerous situation.

What special-K said, if the pressure builds up high enough the battery case can EXPLODE! If your lucky only the engine compartment will get get battery acid all over it, only ruining the paint under the hood, destroying the finishes of the engine compartment, and rotting/corroding hoses along with any aluminum. At worst your face will be under the hood when the battery lets go.........not a good sight when shards of plastic battery case coming flying at your face followed closely by acid.

[project 67 sub]

what about a battery that is just sitting on a chair in my garage.... it has been sitting almost 2 weeks and it does this bubbling boil sound once in a while, any ideas??

[chris71]

Originally Posted by WorkinLonghorn

This is a new one for me. Is it the type of battery with cell caps that you can remove? And you removed them and noted the electrolyte level and corrected with distilled water as needed? I would check the vents and make sure they aren't clogged.A chargeing batttery will make hydrogen and oxygen but the vents shouldn't hiss.

yes is has 2 big caps on top, and i havent checked the level, is there a fill line under the cap? the battery is really clean, no crud on it to clog the vents, maybe some critters got in there?

[hotrodhomi]

Originally Posted by WorkinLonghorn

There is a ring in there. Hopefully someone with more battery knowlege will post. Meantime,pop those covers off with a screwdriver and have a look-see.

DO NOT do this or anything else around this battery (or any battery) without safety glasses. I've had this crap blow up in my face before. I always wear glasses when working with batteries, even just disconnecting them. Be safe.